But CBS News' Dr. Jon LaPook says some headlines have been misleading, and pregnant women should continue taking folic acid.
"There's no doubt that women who have too little intake of folic acid during pregnancy have an increased risk in having kids with severe neurological problems," Dr. LaPook said.
According to LaPook, the report is still very preliminary, and a lot more needs to be studied.
"This does not mean that taking too much B12 or folate causes autism, it's an association," LaPook said. "We do not want women to misinterpret this headline."
To learn more about Dr. LaPook's assessment of the study, watch the video above.